Method of refrigeration.



A. H. EDDY.

METHOD OF REFRIGERATION. APPLICATION FILED JUNE 17. mo.

Patented May 30, 1916;

3 SHEETS-SHEET 2- a 1/2 Efida c%-4a% 1M??? A. H. EDDY.

METHOD OF REFRIGERATION.

APPLICATION FILED JUNE 17. 191-0.

7 3 SHEETS-SHEET 3- Ql 46 W 6?.

" lllll lllll IIIIIIIIHI! 6w llllllllll Patented May 30,1916.

UNITED STATES PATENT OFFICE.

ARTHIIR H. EDDY, 0F WINDSOR, CONNECTICUT, ASSIGNOB T0 CHARLES E.SHEPARD,

0F HARTFORD, CONNECTICUT.

Specification of Ietters Patent.

Patented May so, 1916.

Application filed June 17, 1910. Serial No. 567,408.

To all whom it may concern Be it known that I, ARTHUR H. EDDY, a citizenof the United States, and resident of WVindsor, in the county ofHartford and State of Connecticut, have invented certain new and usefulImprovements in Methods .of Refrigeration, of which the following is afull, clear, and exact specification.

This invention relates to an improved method of practising artificialrefrigeration. In the -general practice of this art, a refrigeratingfluid or gas, generally ammonia, is circulated under pressure in anendless system, in, or suitably adjacent to,'the rooms or spaces to becooled, at which portion of the system the ammonia is allowed to expandin an expansion coil or chamber to absorb heat through the walls of the'coil or chamber from the space outside of those walls. The expandedammonia fluid, or gas, with its absorbed heat, is then pumped' orotherwise conducted to another part of the system, where it isrecompressed, and cooled, to free it from the heat absorbed in theexpansion coils, after which the fluid is again circulated through thesystem as it is needed. In this parativef ease, by varioiis handregulated devices of'the prior art. But where some or all of the roomsor other spaces to be cooled are frequently opened and closed, the coldmate rial taken out, and warm material substituted, the work to be doneby the circulating fluid varies greatly in the differentrooms, and inthe same room. For example, the

refrigerated roomsof a provision store ordicooled goods and replace themwith other goods containing more heat. That heat, with the heat directlyadmitted by the more or less irregular opening and closing of the doors,and varying in amount and temperature according to the season, should beabsorbed by the refrigerating fluid at all times to suit these varyingconditions, so as to maintain the temperatures desired in the respectiverooms, more closely and uniformly than can be done'by personalattendance, or by any hand or other devices known to me in the priorart.

A prime requisite for efliciency and economy is that the refrigeratingfluid shall perform a regulated amount of work at each stage or cycle ofits operation. To accomplish this, the refrigerating fluid should beadmitted to the expansion coils and discharged therefrom only at suchtimes, and in such quantities as are compatible with its properexpansion or vaporization, and consequent absorption of heat from thesurrounding medium to be cooled. Having performed its required duty inany given expansion coil, if the medium surrounding the coil requiresstill further cooling,the fluid should be released in suflicientquantity and its place should be taken by the flow and expansion of thecooled and compressed fluid from the supply pipe in sufficient quantityand for the length of time requiredr to reduce the temperature to thedesired degree as the result of its proper expansion and consequentabsorption of heat from the medium to be refrigerating fluid to and fromthat coil or chamber should be interrupted until'the pressure, againrising above the prescribed degree, calls for a further flow andexpansion of the fluid with the resulting absorption of the heat.

In cases Where two or more refrigerators or cooling. rooms are employedin the'same establishment, it is desirable to operate and controlthem'all in connection with a single circulating system and a singleplant for recompressi'ng and cooling the fluid, the inbers being cnnected with a single supply pipe, and a ultimately into a common returnpipe or lets of the ieXeral expansion coils or chamsystem of pipes,leading to the compressing pump. In such cases it is desirable topredischarging either directly or.

vent the backward inflow into any of the expansion chambers or coils, ofrefrigerating fluid previously discharged therefrom, or,

discharged from another expansion chamber or coil, Which by its pressureand temperature is capable of either absorbing more heat from, or oftransferring some of its own heat to rooms which are already at thedesired temperature. cially where different rooms are to be maintainedatdifferent temperatures, it is desirable, for more complete efficiency,to employ the refrigerating fluid in a series relation to the rooms,absorbing heat from each in succession. On account of the fluent andvolatile eharacter of the ammonia which is commonly employed as acirculating medium when under pressure, it passes with great ease andrapidity through very small openlngs leading into coils of lowerpressure, especially under the pressures or diflerences 1n pressurecommonly employed. For this reason the valves and their seats must fitaccurately together, so as to close tight when it is desired to stop theflo w, and to open to properly graduated and limited extents, inaccordance with the requ1rements of service. In other words, the valvesemployed at points where differences of pressure may occur promptly andautomatically responsive to the changes taking place during theabsorption and transfer of the heat in the cooling chamber. It is foundthat hand regulated valves are unsuited for the purposes contemplatedherein, since they are dependent upon personal attendance and operation,and even with the most careful and constant personal attention, only arough approximation to proper regulating conditions can be obtained bytheir use. This is particularly true in any attempt to regulatediflerent chambers to dilferent temperatures. Even when such handoperated valves are most carefully adjusted according to therequirements of the respective refrigerating chambers which they areexpected to maintain at different temperatures, those adjustments remaineven approximately correct only during the uniform continuance of theexact conditions for which the valves were adjusted. Any change in therelative amount of heat to be absorbed from each chamber calls for aprompt and properly graduated change in the relative adjustment of thevalves, which is impossible with hand regulated devices, even when thenecessity and its extent are apprehended in season. Even if handregulating valves could be adjusted accurately to allow of the propervolume of flow of the refrigerating fluid of different chambers,requiring the same or diflerent temperatures, that adjustment would notbe suitable for In some instances, and espe-' should 'be sensitive,andchanges in pressure; and for that reason would be unsuited for themaintaining of different rooms at different temperatures and. pressuresby a single connected system; for the different pressures wouldobviously equalize through the dilferentvalves, even though the latterwere opened to varying extents to suit the volume of flow requiredfortherespective rooms or chambers. This is equally true whether such valvesare employed at the inlets or outlets of the expansion coils or"chambers. Moreover, they would permit backflow of fluid discharged froma chamber at a higher pressure into chambers intended for a lowerpressure, where both discharge into a conimon return pipe.

A principal object of the present invention is to utilize and direct thenatural and elemental properties and forces resident in therefrigerating fluid and in the heat absorbed in the different stages ofits thermodynamic cycle while performing its functions in the process ofrefrigeration. and thereby to control automatically the How of thatfluid to suit the varying conditions and to accomplish the desiredresults.

A further object of the present invention is to provide for utilizingand directing the aforesaid elemental properties and forces of the heatand of the refrigerating fluid to automatically regulate 1and controlthe flow of refrigerating fluid. from a common source, to a plurality ofcooling or refrigerating-rooms and maintain the same or a differenttemperature in each. independently of the others: and also to dischargeor release the expanded fluid with its varied conditions of heat andpressure. from the respective coils, into othercoils or into a commonreturn pipe. while avoiding backfiow of the fluid discharged from thecoils at a higher pressure into coils under a lower pressure. Thisenables dill'erent refrigerating rooms. supplied by the same circulating system of refrigerating fluid to be maintained at the differenttenuwratures best suited for different purposes. This requirement verycommonly exists in the same establishment: as for example in a provisionwarehouse or market. where it is desirable to maintain differentcommodities at different temperatures.

A still further object of the present invention is to utilize and directthe aforesaid properties and forces of the refrigcrating fluid. and ofthe heat absorbed or to be absorbed thereby. in regulating andcontrolling the fiow of the refrigerating fluid from a refrigeratingchamber. in which the fluid has absorbed a proportionate amount of heat,to one or more additional chambers in series from which the same fluidmay economically absorb a further amount of heat before beingrecompressed and cooled.

matic representation of a circulating sys tem embodying the presentinvention, illustrating three cooling chambers connected to the systemin parallel arrangement. Figs.

2 to 5 inclusive are diagrammatic views representing difieren'tarrangements, and modifications of refrigerating chambers and theirconnections in the refrigerating system. Fig. 2 represents two chamberswith their refrigerating means connected in series. Fig. 3 representstwo chambers arranged in a modified series relation. Fig. 4 representsthree chambers connected in another modified series system. Fig. 5 showsthree rooms or chambers combined and connected in a further modifiedseries similar view of an outlet valve suitable for practising thepresent method, adapted to regulate the outflow of the refrigeratingfluid from the respective coils under the control of the pressure withinthe said coils.

A brief description will first be given of the principal features of thegeneral system represented'in Fig. 1. This shows three refrigeratingrooms or chambers A, B and C, all of which receive refrigerating fluidfrom a single supply pipe 1, through the branch pipes 2; and all threedischarge into a common return pipe 3, through the branch pipes 4. Eachbranch of the system is preferably provided with shut-ofl valves 5 and6,

to enable any one or more of the branches to be entirely shut off .twill, when not wanted in the regular operation of the system. Theexpanded ammonia fluid, or gas discharged into the return pipe 3 iscon-' ducted to a pump 8, which may be driven in any convenient way, asby the belts 9 and 10,

from the electric motor 11. It usually will be found convenient to varythe capacity of the pump 8 in accordance with the work being done; andthis may be accomplished in several ways; for example, by varying thespeed of the motor; or changing the speed in transmission, both of whichways are illustrated herein. The variabl transmission device hereinshown consists of the cone pulleys 12 and 13, provided'with a belt 14,the position of which is controlled by a belt shifter 15, operated by alever 16, pivoted at 17, and worked by its connection with the plunger18, leading to a piston or diaphragm in the pressure chamber 19, whichconnects by means of the pipe 20 with the common return pipe 3.Increasing pressure in the return pipe, due to activity in the heatabsorbing function,' is thus transmitted to the pressure chamber 19,from which movement is transmitted by the described connection to thbelt 14, shifting it to a position on the cone pulleys 12 and 13, whichincreases the speed of the pump, the parts being designed andproportioned so as to vary the speed in approximate proportion to thework being done. Or the lever 16 may be connected with the handle of acontroller 21 employed to control the speed of the electric motor. It

is also desirable in some, if not in most, vinv stances, to provide forautomatically stopping the pump when the'discharge of ex panded fluidceases, and to automatically start the pump again whenever the risingpressure of the discharged fluid demands it. This is herein shown to beaccomplished by means of a piston or diaphragm in a pressure chamber 22connected by means of the branch pipe 23 with the common return pipe 3.The piston or diaphragm is connected by means of the rod 24 with theswitch lever 25, and moves the said lever according to the pressure ofgas in the return pipe into contact with the terminals 26 or 27 thewires of which lead'to a circuit maker and breaker 28, connected withthe motor starter 29, which in turn is-connected with the motor 11.These electrical connections may be of various kinds, and are so wellunderstood that no occasion is seen for describing them here in detail.-

The pump 8 operates to draw in the expanded refrigerating fluid or gasfrom the return pipe 3, and recompress it. The compressedfluid leavesthe pump through the .pipe 32, which conducts it to any ap )roved meansfor extracting the heat absorbe in its previous cycle of operation, andprepares it for the next cycle. The means herein shown consists of acoil 33 connected with the pipe 32 and immersed in water contained inthethrough the outlet 39 into any convenient waste pipe.

The n shown to be connected in parallel relation to the system, theoperation of each branch system being confined to its own room. Thesethree rooms are herein shown to be provided with different forms andarrangements of expansion coils, showing the adap-.

tation of the system to diverse requiremerits. The refrigerating fluidconducted intoeach room or chamber by its-branch supply pipe 2, isadmitted to the expansion coils within the chambers, and afterperforming its allotted work is released and discharged through itsbranch outlet 4-into the common return pipe 3. According to the presentinvention, the flow of the refrigcrating fluid to, through, and out ofthese coils, is automatically controlled by the elemental forces andproperties of heat, expansion, and consequent pressure of therefrigerating fluid in the coil, opposed and counterbalanced to a degreeby the expansive action of the heat yet to be absorbed from the room orchamber. Hence the flowmay be said to be subject to the dual control ofthe heat already absorbed and confined in the coil, and of the heat yetto be absorbed.

Various forms of valves may be employed at the inlets and outlets of thecoils, some of which are shown in my own prior patents. The inlet valveillustrated herein is of the automatic expansion type shown in my U. S.Patent 853,505, granted to me May 14, 1907. This valve as shown in Fig.6 has a disk valve 45 located on the inlet side of the valve seat 46,the stem 47 of the valve is connected on the outlet side of the valveseat with a diaphragm 48, above which is a pressure 'chamber 49, toWhich the admitted refrigerating fluid passes when the valve 45 isopened, and from which it finds its way through the passage -50 to theexpansion coil 51. Thus the diaphragm is subjected on one side to thepressure of the fluid in the chamber 49, due to the expansion of therefrigerating fluid in the coil 51, and is subjected on its oppositeside to the pressure 'of a spring 52 interposed between the diaphragm 48and another. diaphragm 53, which upon its under side is exposed to thepressure due to the expansion of a liquid, such as alcohol in thethermic receptacle 54, which is placed in any desired portion of theroom or compartment to be cooled. The under side of the diaphragm 48 isalso subjected to the pressure of a spring 56,. the tension of which canbe adjusted by hand, by means of the right and left hand nut orturnbuckle 57. so as to adjust the balance of the opposing forces withinthe valve to suit desired temperatures. The details of construction ofthis valve are fully shown and described in my aforesaid Patent No.853,505.

The expansion coils may be disposed in any convenient or desired WayWithin the chambers, and may be employed in direct contact with the air,as in the case of the coils 51 and 59 in the rooms A and B; or they maybe placed in tanks or boxes, as shown by the passage 67. The valve isyieldingly held to its seat by means of a spring 68, interposed betweenthe disk plate 69 and a collar 70. The tension of the spring may be adjusted by means of the screw 71, so as to hold the valve head 64 closeduntil overcome by the desired or predetermined pressure of expandedfluid in the coil. Thus the flow of cooling fluid through the coil isautomatically controlled at both ends of the coil by variations in theopposing and correlated pressures. When the temperature in a coolingroom reaches a desired or prescribed point, these opposing forces are inequillibrium, and the valves close and remain closed, thereby stoppingall flow of the refrigerating fluid. As the temperature in the room israised by the opening of the door or otherwise, it takes effect upon thethermic receptacle 54, and by the consequent expansion raises thediaphragm 53, and opens the valve 45, overcoming the pressure against.the upper side of the diaphragm 48 of the proper temperature relationis reached. If

a considerable amount of heat is to be absorbed, due to the frequentopening of the room, or from any other cause, the expansive actionwithin the thermic receptacle 54 continues in accordance with the heatto be absorbed, thereby keeping the valve 45 open against the closingaction of the pressure in the coils. The tension of the outlet valve 63is adjusted to a point which will hold the refrigerating fluid in thecoil up to the point at which it .receives its desired amount of heat,beyond which point the increasing pressure of the'fiuid opens the valve63, and

, resented in Fig. 4; or into the coils of other w chambers in. thesystems illustrated in Figs.

permits the heated fluid to discharge into the return pipe 3, in thearrangement .rep-' 2 to 5 inclusive. 1 The area of the outlet port 65,the tension of the spring 68, and the area of the diaphragm 66 are soproportioned as to prevent the returnflowof heated fluid that has beendischarged from the same or another coil. This, especially in the caseof rooms malntaimng different temperatures, effectually prevents thebackward flow of fluid or gas at a higher pressure, into a coil intendedfor a'lower pressure. This.

prevents any backward transfer of heat which has once been absorbed.This internal control of the flow ofthe liquid through i the rooms toberefrigerated, entirely eliminates the external control or influence ofthe varying pressures 1n the return pipe'3 and its branches, and of thepump employed for recompressing the fluid. It is desirable to' from aplurality of chambers in which dif:

ferent temperatures are to be maintained. As an illustrative example, itmay be as sumed that in the parallel arrangement illustrated in Fig. 1,the chambers A, B and .C'

are to be maintained at temperatures of 10, 30 and 20 degrees,respectively, and that the coil temperatures are about 20 or-25 degreesbelow the respective chambers, in which case the coils work attemperatures of approximately 15, 5 and'O degrees, respectively.

By reference to standard tables showing the properties of saturatedammonia gas, it will be found that the equivalent gage pressures forthese temperatures are about 28, 20 and 15 pounds, respectively.Therefore, the outlet valves 63. are adjusted to release at pressures of28 pounds from the coil 51 of the room A, at 20 lbs, from the coils 59and 60 of the room B, and at 15 lbs. from the coil 61 of the room C. Theworking pressure in the supply pipe 1 is assumed to be about 140 lbs.The inlet valves are adjusted so that-with these back pressures of 28',20 and 15 lbs., respectively, they will be opened by their respectivethermostatic re ceptacles 54 in opposition to these back pressures, whenthe temperatures of their respective chambers, exceeds the assumedlimits of 40, 30vand 20 degrees for the chambers A, B and C,respectively. Under these conditions, starting from equilibrium, a riseof temperature in one of the chambers would operate through itsthermostat 54 to open the inlet valve 44, thus admitting a supply ofammonia, which by its expansion in the coil would, as Well understood,absorb heat from the chamber. This absorption of heat would increase thepressure of the gas in thecoil until it. overcomes the resistance. ofthe gas outlet valve. This transfer of the heat from the chamber and itsconversion into pressure in the coil serves to balance the forcescontrolling the inlet valve, so as to mostat 54 being overcome by therising-back pressure in the coil. If the coil is small relative to thesize of the chamber, or if the chamber is frequently opened and moreheat admitted, then the continuing pressure from the thermostat is notovercome by the rise of pressure in the coil, due 'to its absorption Iof heat. In such cases the expansion in the sistance of the outletvalve, thus stopping the flow of the fluid and the consequent waste ofenergy needed to recompress it.

ment illustrated in Fig. 1, different temperatures desired in thedifferent chambers A.

B, C, are obtained by suitable adjustment of their respective inlet andoutlet valves, so that the elemental forces in each will be balanced atthe various desired temperatures. k a

In the series arrangement shown in Fig. 2 as an, illustrative example,it may be as sumed that the rooms 77 and 79 are to be maintained attemperatures of 35 and 25 degrees Fahrenheit, respectivel and that thisrequires the coils 76 and 78 to be respectively maintained at 15 degreesand 5 degrees Fahrenheit. It is assumed also that the relative sizes anduses of those rooms are such that room 79 gives up to its refrig cratingcoil 50% more heat than room.77 does to its coil. 'It is also assumedthat the supply pipe 1 supplies liquid ammonia at degrees Fahrenheit atthe pressure corresponding to the pressure of saturated ammonia vapor atthat temperature, namely about 125 pounds per square inch gage pressure.The outlet valves 63 of rooms 77 and 79 are set at 63 and 19 pounds,respectively, gage pressure. The inlet valve {1 1 is adjusted to furnishrefrigerating fluid in such quantity that each pound of the fluidabsorbs about 160 British thermal units from room 77. Each pound of thefluid will also absorb 50% more than this from room 79, or 240 B. T. U.Under these circumstances the fluid at the exhaust end of coil 76 will70 close it; the'falling pressure from the ther- Obviously in thisparallel system or arrangeconsist of about 55% liquid and 45% vapor,while the fluid at the exhaust end of the coil 78 will be about 7%liquid and 93% vapor.

Various ways are illustrated in Figs. 2 to a coil 78 of the chamber 79.These coils are scribed. But when, for any reason, the coil provided asshown in the figure with inlet and outlet valves 44 and 63' of thegeneral char acter previously described herein, operating under thecontrol of the heat absorbed and to be absorbed for regulating the flowof refrigerating fluid, andpreventing the return flow.

In the arrangement shown in Fig. '3, the two 'rooms or chambers 81 and82 are served by a branch arranged in series, consisting of the coil 83in the room 81, discharging into the coil 84 in the room 82. In thisarrangement, however, the room 82 is provided with an addit'onalauxiliary or supplemental branch of the system,operating through the'coil 85. So long as the heat absorbing capacity of the coil 84 issufficient to keep the room 82 at the desired temperature, the auxiliarycoil 85 remains inactive, its inlet valve 44"being kept closed by theaction of its thermic receptacle 54, as previously dein room 81 isinactive, or if active the fluid discharged therefrom is incapable ofabsorbing the heat from room 82 with suflicient rapidity, thetemperature rising above the point predetermined for that room, operatesthrough the thermic receptacle 54 to open the valve 44, thus admitting asupply of fluid to the coil 85 which operates as already described,until the temperature is reduced to the desired point. p

In the arrangement shown in Fig. 4, three rooms are provided withexpansion coils arranged in a series relation, with an auxiliary branchin the third or last room. The coil 87 in the first room 88 receives itsfluid from the common supply pipe 1 through the inlet valve 42 asrequired, and as determined by the balance of the opposing action of thefluid in the coil 81 and in'the thermic receptacle 54, as previouslydescribed. The fluid released or discharged from the coil 87 through theoutlet valve 63 passes hrough a coil 89 in room 90 whence it isdischarged through another outlet valve 63 into the common return pipe3, this branch thereby acting inseries in thetwo rooms 88 and 90. Asimilar branch of the system acts in series through the coil 91 in theroom 90, and the coil 92 in room 93. In addition to this seriesrelation, the room 93 is provided with an auxiliary branchsystem of itsown, operating through the coil 94. These coils are provided with theinlet valves 44 and outlet valves 63, previously described.

' perature.

A still further modified arrangement is shown in Fig. 5, in which theexpansion coil 96 in the room 97 connects in series with the coil 98 inthe room 99, and with the coil 100 in room 101. An auxiliary branch coil102 in room 99 receives 'the'refrigerating fluid independently, underits own control, from the common supply pipe 1, and discharges into thepipe connecting the coils 98 and 100 in series, thus itself becomingauxiliary to the series. Similarly in room 101 an auxiliary branch coil103 receives refrigerating fluid independently from the supply pipe 1,and discharges into the pipe duced within the coil by the heatabsorption and consequent expansion of the fluid confined therein by theoutlet valve are cons'tantly opposed to each other, being balanced so asto close the inlet valve when the room is reduced to the desiredtemperature, and to open the inlet valve when the temperature is abovethe desired point, serving also to open the outlet valve when thepressure in the expansion coil, caused by the absorption of heat,indicates that it has absorbed its desired amount or quota of heat, andthat a further flow of the refrigerating fluid is needed to absorb theremaining heat.

'An important advantage of the present system is its adaptation tomaintaindifferent rooms connected with the same system, at differenttemperatures, independently of each other. In the parallel arrangementof the system, illustrated in Fig. 1, each room is cooled by a singleindependent coil, and any room may be carried at the desired tem- But ina series arrangement of the system, where it is desired to maintaindifferent temperatures in the different rooms, the series arrangementshould preferably be so that the flow will be from rooms requiringhigher temperature to rooms requiring lower temperature, so that the gasafter absorbing an economical amount of heat from a given chamber,passes to a chamber in which lower temperature is required, and byfurther expansion is adapted to absorb heat therefrom and thereby lowerthe temperature. For example, in the arrangement shown in Fig. 3, it maybe assumed that the room 81 is to be maintained at 15 degrees, and theroom 82 at 10 degrees. In this case the fluid, after absorbing asuitable amount of heat in the expansion coil from the room 81, passesto and is released into the coil 84 in the room 82, in which itundergoes a fur ther expansion, and is thereby adapted to absorb anadditional amount of heat.

In the arran ement shown in Fig. 9, the gas in the coil 8%, havingabsorbed heat from the room 88 and thus reduced the temperature of thatroom to an economical degree system illustrated in Fig. 5, the seriesarrangement is shown to extend into the three chambers, taking fromeachits permissible amount or quota of heat. I

These cooling rooms, or the separate expansion coils, may be regarded asindependent units, which may be assembled with other similar units atthe pleasure of the designing engineer, in series or in parallel, on inboth ways. The coils may receive their refrigerating fluid in seriesfrom each-,other, when the conditions are such that the" gas or fluiddischarged from one coil is still capable of doing useful work byfurther expansion in another coil, thus exhausting its heat absorbingcapacity before being finally discharged into the common return pipe.Suitable auxiliary or supplemental coils may be provided whereverrequired, receiving their supply directly from the common supply pipe 1,automatically remaining closed as long as they are not required; butautomatically opening and coming into action as soon as their servicesare called for. A plurality of coolingrooms thus equipped and connectedin the system either in series or in parallel, or both, may bemaintained at different desired temperatures, receiving theirrefrigerating fluid from a common source of supply, utilizing to theutmost its -heat absorbing capacity and returning it to the pump througha common return pipe, without any backflow or other interference betweenthe respective coils or rooms.

with, but a much greater efficiency is secured than could be obtained bythe most careful and devoted personal attention and services, because ofthe constant readiness and prompt response and efficient action of thesystem. This is due primarily to the fact that the system is at alltimes under Not only arethe services and attention of human operatorsdispensed expands the refrigerating fluid, the increasing pressure ofwhich acts upon the inlet valve and opposes its opening action; and at.

the same time extends forward to the outlet valve, tending to openit.When the desired temperature is reached in the cooling room, theseforces are balanced andthe refrigerating fluid is held back, thuspreventiing its waste by unnecessary action, witi the consequentnecessity for recompression. A disturbance of the balance of theelemental forces promptly operates to start the re- I 'frigeratingaction, which is kept up with an activity suited to varyingrequirements, until the temperature is again reduced to the requireddegree, and the forces again balanced. Thus the system goes onindefinitely.

It will be understood that this invention is not limited to the specificarrangements herein shown or suggested, since the invention can andshould be adapted to different conditlons 1n various ways, according tothe skill and judgment of some one familiar of pressure of the confinedfluidto control the release of the expanded fluid and the admission of afurther supply of the fluid.

2. The method of refrigeration, which consists in confining a portion ofa supply of refrigerating fluid within the influence of the space to becooled, from which the heat is absorbed by the expansion of the fluid,directing the resultant rising pressure to release some ofthe confinedfluid, and also utilizing the subsequent resultant falling of thepressure to control-the admission of a further supplyof fluid.

3. A continuous and self-regulating method of refrigeration, whichconsists in yieldingly confining a portion of a supply of refrigeratingfluid in an expansion coil or chamber, whereby heat is absorbed by theexpansion of the fluid within the coil, and utilizing the resultantsuccessive increases of pressure within the coil to re-.

lease successive portions of the expanded plies of the fluid to the coiland releasing successive portions of the expanded fluid from the coil,both under the control of the 'ariations of the pressure in the coil.

A process of refrigeration, which consists in yieldingly confining aportion of a supply of refrigerating fluid, expanding the confined fluidand increasing its pressure by the absorption of heat from its surround-1ngs, utilizing the pressure to automatically release a portion of theexpanded fluid, and

temperature in the said surroundings to an tomatically regulate theadmission of more refrigerating fluid from the sald supply.

7 The method of automatically regulat ingthe flow of refrigerating fluidfrom a common source, and maintaining desired temperatures in differentchambers inclependently of each other, which consists in yieldinglyconfining portions of the fluid within the respective chambers,expandingtherespective portions of fluid and increasing their pressureby the absorption of surrounding heat, and utilizing the rising pressureof each expanding portion to automatically and successively release theexpanded fluid, and to utilize the resultant reduction in pressure toregulate the admissionof more fluid from the common source of supply.

8. The method of automatically regulating the flow of refrigeratingfluid from a common source, to maintain the same temperature ordifferent temperatures in a plurality of refrigerating chambers, whichconsists in yieldingly confining portions of the fluid in differentexpansion coils for the respective chambers, and utilizing the risingpressure of the fluid confined in each coil to release expanded fluidfrom and hold back fresh fluid from that coil; and also directingthermostatic pressure under the .influence of the changing temperaturesof the respective chambers to assist the admission of fresh fluid totheir respective coils.

9.The method of automatically regulating the flow of refrigerating fluidfrom a common source in series relation through a plurality ofrefrigerating chambers to maintain desired temperatures in each chamberindependently of the others, which consists in separately confining thefluid for the respective chambers, and directing thermo-- staticpressure in each chamber under the influence of rising temperature inthat chamber to admit more fluid and also utilizing the pressure of theconfined fluid within each chamber to oppose the said admission of morefluid to that chamber.

10. The method of automatically regulating the flow of refrigeratingfluid from a common source in series relation through a plurality ofrefrigerating chambers to maintain desired temperatures in each chamberindependently of the others, which consists in separately confining thefluid for the respective chambers, and directing thermostatic pressurein each chamber under the influence of rising temperature in thatchamber to admit more fluid and also utilizing the pressure of theconfined fluidwithin each chamberto oppose the said admission of morefluid to that chamber, and also in conducting the released fluid fromone chamber to another chamber, thereby utilizing the same fluid in asuccession of chambers to absorb heat from each in succession.

In Witness whereof I have signed my name to this specification in thepresence of two subscribing Witnesses, this 13th day of June, 1910.

ARTHUR H. EDDY.

Witnesses e CHARLOTTE S. HULL, CAROLINE M. BREQKLE.

